Responses of Soil Exchangeable properties, Growth and yield of Orange-Fleshed Sweet Potato (Ipomoea batatas (L) Lam) to the application of N, P, and K fertilizer combination rates at Ikwo, Abakaliki Nigeria

Abstract

AThis study was carried out on a degraded Ultisol at Teaching and Research Farm, Faculty of Agriculture, Alex Ekwueme Federal University, Ndufu-Alike (AEFUNAI), Abakaliki Ebonyi state during the 2022 and 2023 planting seasons, to assess the responses of soil exchangeable properties, growth and yield of orange-fleshed sweet potato (OFSP) to the application of N, P and K fertilizer rates at Ikwo, Abakaliki Nigeria. The treatments were Nitrogen fertilizer at four levels; 0, 45, 90, and 135 kg/ha; Phosphorus fertilizer at four levels; 0, 15, 30, and 45kg/ha and Potassium fertilizer at four levels; 0, 20, 40, and 60 kg/ha. The experiment was a factorial experiment arranged in a Randomized Complete Block Design (RCBD) with three (3) replications. Growth and yield data were collected on OFSP.  Soil samples were collected with a soil auger at a depth of 0 to 20cm at the end of the experiment for soil exchangeable properties determination. All data collected were subjected to ANOVA for a factorial experiment in RCBD at 5% probability level. The results showed that different combined rates of NPK fertilizers significantly (P < 0.05) improved soil exchangeable properties and growth and yield parameters of orange-fleshed sweet potato compared to the control in the two years of the experiment. However, the application of N, P and K at the rate of 90kgN-45kgP₂O₅-60kgK₂O recorded the highest number of OFSP leaves, number of branches, vine length, weight of OFSP storage root and total storage root yield in 2022 and 202.